drawing a triangle in dbgrid

Hello guys,

Maybe you can help me with this function that I have to draw a triangle in my dbgrid. This function is used to show how title was clicked and ordered.

I'd like to have both way, a draw for "asc" and another for "desc"

or maybe this code can be more simple, please, take a look at it:

You can test it with a simple grid linked in a dataset

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, DBTables, Grids, DBGrids, StdCtrls, Buttons;

type
  TForm1 = class(TForm)
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    Query1: TQuery;
    BitBtn1: TBitBtn;
    procedure DBGrid1TitleClick(Column: TColumn);
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure DrawMarc(Grid: TDbGrid; Column: TColumn; MaxColumn: integer;
  ini: integer=0);
  var x, i : integer;

  procedure Draw(xx: integer);
  begin
    grid.Canvas.FillRect(Rect( xx, 6, xx + 6, 14));
    //draw a triangle
    grid.Canvas.MoveTo(xx,6);
    grid.Canvas.LineTo(xx + 6,6);
    grid.Canvas.LineTo(xx + 3,12);
    grid.Canvas.LineTo(xx,6);
  end;

  procedure Paint(min, top: integer);
    var max, lin : integer;
  begin
    max := min + 7;
    lin := 2;
    While min +1 < max do
    begin
      if lin = 2 then
      begin
        inc(min);
        dec(max);
        lin := 1;
      end
      else
        inc(Lin);
      inc(top);
      grid.Canvas.MoveTo(min, top);
      grid.Canvas.LineTo(max, top);
    end;
  end;

begin
  x := 0;
  grid.Canvas.Brush.Color := $00D0EFF2;

  // limpa marca antiga
  for i := 0 to  MaxColumn -1 do
  begin
    x := x + Grid.Columns.Items[i].Width;
    if i > 0 then
      x := x + 1;  // soma 1 px para o desenho da linha.

    if i < ini then
      continue;

    if Grid.Columns.Items[i] = Column then
    begin
      grid.Canvas.Pen.Color := clOlive;//$00D0EFF2;
      Draw(x - 10);
      Paint(x - 10 ,6);
    end
    else
    begin
      grid.Canvas.Pen.Color := clsilver;
      Draw(x - 10);
    end;
  end;
end;

procedure TForm1.DBGrid1TitleClick(Column: TColumn);
begin
  drawMarc(DBGrid1,column,10, 0);
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  query1.Open
end;

end.

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